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August 14, 1996

Hepatitis A Vaccines-Reply

Author Affiliations

Merck Research Laboratories West Point, Pa

JAMA. 1996;276(6):450. doi:10.1001/jama.1996.03540060026020

This article is only available in the PDF format. Download the PDF to view the article, as well as its associated figures and tables.


In Reply.  —Several points raised by Dr Krause merit clarification. First, Merck was granted a US license for Vaqta (hepatitis A vaccine, inactivated), its hepatitis A vaccine, on March 29,1996; Vaqta went on the market in May 1996. The compositions of Vaqta and Havrix differ (Table). Whether these compositional differences will translate into better safety and tolerability is a scientific question that can only be answered by comparative trials. These trials for rare postvaccination adverse events will, by definition, require adverseexperience report surveillance of large populations of vaccinees that should be accruable over 1 or 2 years.